His latest book, the graphic-novel biography “Joseph Smith and the Mormons,” will be published at the end of July. It is a nuanced and complicated portrait of Mormonism’s founder. Using Smith’s short life, from his childhood in upstate New York to his violent death when he was thirty-eight, at the hands of a mob in Illinois, Van Sciver tells his interpretation of the religion’s early years. Van Sciver’s Smith is a would-be prophet, driven by faith yet full of human frailty, who rose from humble beginnings to build a quintessentially American religion in the expansionist years of the eighteen-hundreds. We talked to the author about what compelled him to take on this book.